JPH03216676A - Method and device for recording color - Google Patents

Abstract

PURPOSE:To attain fast, low-cost color recording with small-sized constitution using a normal electrostatic latent image carrier by exposing the electrostatic latent image carrier to reflected light from an original which is not passed through a color separating means and forming and developing a 2nd positive latent image with 2nd toner. CONSTITUTION:A 1st positive latent image is developed by a 1st developing unit 13 with 1st toner. After the electrostatic latent image carrier 10 makes one turn, only an area on the electrostatic latent image carrier 10 which corresponds to a specific separated area on the original is charged electrostatically and selectively by an ion recording head 20 and then the electrostatic latent image carrier 10 is exposed to the reflected light from the original which is not passed through an optical filter 8 to form the 2nd positive latent image, which is developed by a 2nd developing unit 14 with 2nd toner. The developed image on the electrostatic latent image carrier 10 is transferred to a recording sheet by a transfer means and fixed by a fixing means. Consequently, the fast, low-cost color recording method where the normal electrostatic latent image carrier is usable is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color recording method and an apparatus thereof, and more specifically, it relates to a color recording method and an apparatus thereof, and more particularly, it relates to a color recording method and an apparatus thereof, and more specifically, it relates to a color recording method and an apparatus for color recording. The present invention relates to a color recording method and apparatus that can perform color copying using two colors.

[Prior Art] As a conventional recording method and apparatus of this type, for example, Japanese Patent Application Laid-open No. 6
0-239727 and JP-A-60-239764, in which a toner image is transferred multiple times onto a recording sheet to form a multicolor image, or JP-A-56-1953. The laminated photoreceptor system described in 2003 is known.

[Problems to be Solved by the Invention] However, the former method, that is, a method in which a toner image is transferred multiple times onto a recording sheet to form a multicolor image,
Because a two-color image is formed by repeating latent image formation, development, and transfer twice, there is a drawback that the copying speed is significantly lower when making two-color copies than when making single-color copies, and because the images are overlapped on the recording sheet. , high-precision registration is required, which increases the complexity and cost of the device, and
There is a problem in that the conveyance path of the recording sheet increases the size of the apparatus. There is a superimposed development method as a means to solve this problem, but in this method, when a normal Carlson process photoreceptor (electrostatic latent image carrier) is used, the black image is removed using only an analog optical system. Since it cannot form an image, it has the disadvantage that it cannot perform multicolor copying using black and other colors.

On the other hand, two-color copying is performed using the latter, that is, a laminated photoreceptor and an analog optical system (here, analog optical system refers to a device that uses mirrors and lenses to directly guide a light image to the photoreceptor). In this method, since the electrostatic latent image portion corresponding to the A-color image and the electrostatic latent image portion corresponding to the B-color image are formed by photoreceptor surface potential distributions of opposite polarity, the latent image boundary area due to the fringe electric field is formed. This has the problem that color mixing occurs and the quality of black images deteriorates compared to conventional black and white copying machines. Furthermore, since a special laminated photoreceptor capable of forming a bipolar latent image is used, the process of forming an electrostatic latent image is complicated, resulting in an increase in cost.

Furthermore, a method is known in which a specific image is extracted using an image sensor and negative exposure is performed using a light output means (Japanese Unexamined Patent Publication No. 6
(Refer to Publication No. 3-180975) In this method, since it is a digital method, if image quality equivalent to that of an analog method is required, both the image sensor and the light output means must have high resolution, which increases costs. It has the disadvantage of becoming.

Therefore, the high speed that ordinary electrostatic latent image carriers can be used,
At present, there is a desire to develop low-cost color recording methods and devices.

The present invention was made in view of the above circumstances, and its purpose is to provide a compact, high-speed, and low-cost color recording method and device using a normal electrostatic latent image carrier. It is something.

[Means for Solving the Problems] In order to achieve the above object, the color recording method of the present invention includes uniformly charging an electrostatic latent image carrier, and then separating a specific color from a document by a color separation means. a first step of exposing the electrostatic latent image carrier to the reflected light to form a first positive latent image, and developing the first positive latent image with a first toner; and rotating the electrostatic latent image carrier once. After that, only the area of the electrostatic latent image carrier corresponding to the separated specific color area of the original is selectively charged, and the electrostatic latent image carrier is charged with light reflected from the original that does not pass through the color separation means. The present invention is characterized by comprising a second step of exposing to light to form a second positive latent image and developing the second positive latent image with a second toner. The color recording apparatus includes an electrostatic latent image carrier, a uniform charging means, an ion recording head, an optical means including a color separation means for guiding reflected light from an original onto the electrostatic latent image carrier, and the above-mentioned electrostatic latent image carrier. an optical path dividing means provided in the optical path of the optical means; an image reading means provided in the divided optical path; and a color determining means for determining a specific color area in the document based on the output of the image reading means. and a plurality of developing means for properly developing the positive latent image formed on the electrostatic latent image carrier.

In this invention, the electrostatic latent image carrier has a first positive latent image in which a specific color is separated from the original by a color separating means;
It can be belt-shaped or drum-shaped as long as it forms a second positive latent image that is exposed to light reflected from the original that does not pass through the color separation means. For example, it can be shaped like a belt or a drum. (OPC) photoreceptor can be used.

The above-mentioned ion recording head may be of any type as long as it generates ions by applying a high voltage to a discharge electrode. For example, a high voltage is applied to a wire electrode stretched within a shield to generate an ion current. At the same time, it is possible to use an ion recording head in which ions are controlled dot by dot by an electric field formed by applying a voltage to a control electrode.

The color separation means of the optical means guides any color portion of the reflected light from the original onto the electrostatic latent image carrier, and can be formed of, for example, an optical filter that blocks specific colors. Further, the optical path splitting means provided in the optical path of the optical means guides a part of the reflected light from the original to the image reading means, and can be formed of, for example, a half mirror.

Further, the color discrimination means discriminates a specific color region in the light reflected from the original, and can be formed by, for example, a signal processing circuit.

In addition, the developing means is for regular development of the positive latent image formed on the electrostatic latent image carrier, and includes a separated specific color of the original and a plurality of developers of colors other than the specific color. Formed using a developing device.

[Effect] The above technical means works as follows.

After the electrostatic latent image bearing member is uniformly charged by the uniform charging means, it is exposed to reflected light from the document with a specific color separated by the color separation means to form a first positive latent image. One positive latent image is developed with a first toner in a first developing means. Next, after the electrostatic latent image carrier is rotated once, only the area of the electrostatic latent image carrier that corresponds to the separated specific color area of the document is selectively charged by the ion recording head, and then the electrostatic latent image carrier is charged selectively by the ion recording head. The electrostatic latent image bearing member is exposed to light reflected from the document that does not pass through the color separation means to form a second positive latent image, and this second positive latent image is transferred to the second toner in the second developing means. and developed. The developed image formed on the electrostatic latent image carrier is transferred onto a recording sheet by a transfer means and then fixed by a fixing means.

By performing the first and second latent image formation and development,
Normal color recording is performed.

In addition, when changing part of the part other than the specific color to another color after forming the first positive latent image, the color conversion part is developed by the first developing means after the charge is removed, and then the color conversion part is developed by the first developing means. After only the area of the electrostatic latent image carrier corresponding to the area is charged by the ion recording head, a second positive latent image is formed in the same way as in the above-mentioned normal color recording, and the color conversion part of the specific color is charged. Recording takes place.

Furthermore, when additionally writing a specific color portion after forming the first positive latent image, after the first development, a latent image in the area of the additional writing portion is formed by the ion recording head, and then the second developing means It can be developed.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic sectional view of a color recording apparatus according to the present invention. Here, a black and red recording device using black and red toners will be described.

The color recording apparatus of the present invention includes a platen glass 2 on which an original 1 is placed, a lamp 3 that illuminates an image on the original, a mirror 4 that guides a light image corresponding to the image on the original, a half mirror 5, and a lens. 6; an optical filter 8 inserted between the analog optical system 7 and an electrostatic latent image carrier 10 (hereinafter referred to as a photoreceptor);
An image sensor 9 is an image reading means that receives the light transmitted through the half mirror 5! And this image sensor 9a
The color determining means 9b (hereinafter referred to as a signal processing circuit) is provided for determining a specific color area in a document based on an image signal obtained by reading an optical image.

Further, the photoreceptor 10 is supported so as to be rotationally driven in the direction of arrow A, and on its outer periphery, a charger I+ for uniformly charging, an ion recording head 20, a light output device I2, a first
developer l3, second developer l4, pre-transfer corotron 1
5. Transfer corotron 16a and peeling corotron 16b
A static eliminating corotron 17, a cleaning device 18, and a static eliminating lamp 19 are arranged. Note that the photoreceptor 10 uses an organic (OPC) negatively charged photosensitizer.

The image signal output from the image sensor 9a is processed by a signal processing circuit 9b, and connected so that the ion recording head 20 and/or the light output device 12 are driven according to a signal of a specific color component in the image signal. has been done.

As shown in FIGS. 2 and 3, the main portion of the ion recording head 20 includes a discharge wire 21 and a shield 22 surrounding the discharge wire 21. In this case, the shield 22 is made of stainless steel or the like, and has slits 2 parallel to the longitudinal direction on its upper and lower surfaces.
3. 24 is formed.

Further, a substrate 26 is fixed to the lower part of the shield 22 via a spacer 25 formed of an insulating material.
4, control electrodes 27 corresponding to the printed dots are sequentially arranged at a predetermined density (for example, 4 electrodes/mm). An image control voltage is applied from the drive circuit 28 to each control electrode 27. Note that a power source 3 is connected to the drive circuit 28 of the control electrode 27 and the shield 22.
1a is connected. Further, as shown in FIG. 3, the shield 22 of the head having the above structure is connected to a power source 31a near the photoreceptor IO with a counter electrode 29 disposed behind it, and the power source 31 is connected to the discharge wire 21. It is placed in the same condition.

Further, the counter electrode 29 is connected to ground 32.

In the ion recording head 20 configured as described above, air introduced into the shield 22 from the slit 23 as shown by arrow B flows out from the slit 24, and further includes a substrate 26 on which the shield 22 and control electrodes 27 are arranged. The photoreceptor 1o is reached as shown by arrow C through the gap between the photoreceptor 1o. Then, negative ions 33 generated by applying a voltage to the discharge wire 21 move along with the air flow and move onto the photoreceptor 1.
reaches 0. As a result, a uniform ion flow is formed on the photoreceptor 10. When a voltage is applied to the control electrode 27 with this ion flow formed, an electrostatic field is formed between the control electrode 27 and the shield 22, and this electrostatic field blocks the ion flow at that portion. Therefore, in this type of recording device, by controlling the voltage application to each control electrode 27 based on image information, the ion flow reaching the photoreceptor 10 is controlled dot by dot, and the unblocked negative ions 33 are shielded. 22 and control electrode 27
The electrostatic latent image is formed on the photoreceptor IO by passing through the gap between the head 20 and the photoreceptor 10, and forming an electrostatic latent image on the photoreceptor 10 by the electric field between the head 20 and the photoreceptor 10. There is.

Note that since the photoreceptor IO forms a two-color image in two rotations, the cleaning device 18 is configured to be retractable. Furthermore, since the toners in the first developing device 13 and the second developing device 14 have the same polarity, in order to prevent color mixing and mixing, the developing device 13 that does not perform development must be
3. It is necessary to remove the 14 spikes from the developer carrier 34 (developing roll) or to make the entire developing device retractable.

Next, embodiments of the color recording method of the present invention will be described.

◎First Embodiment FIGS. 4(a) to 4(g) are explanatory diagrams in the case of two-color copying of black and red.

Two-color copying of black and red is performed in the following steps.

(2) Charging The surface of the photoreceptor IO is uniformly charged to -800 (V) by the charger 11 (see FIG. 4(a)).

(1) First Exposure The reflected light image from the original 1 is exposed onto the photoreceptor 10 with the red area removed by the optical filter 8 to form a first positive latent image (see FIG. 4). b)).

At this time, the surface potential of the black part was -800 (V), and the surface potential of the red and white parts was -100 (V).

■The first positive latent image formed on the first black developing photoreceptor 10 is coated with black toner by the first developing device 13 to form a first developed image (see FIG. 4(c)). ). At this time, 2 of 10 charges
component-based black toner is used, and the developing bias VB
+ was −250 (V).

(2) Static Elimination Static electricity is removed from the surface of the photoreceptor by the AC voltage applied to the corotron 17 (see FIG. 4(d)).

At this time, the surface potential of the black part was -100 (V), and the surface potential of the red and white parts was -50 (V).

Note that during the above-mentioned static elimination, the image area is charged with + ions to prevent the polarity of the black toner from being reversed. Furthermore, the black image portion potential Vl1 and the background portion potential V after static elimination
The relationship between BK is I Vll I > I V [K I tona6yo5nit
Le.

By doing so, it is possible to suppress the occurrence of disturbance of the toner image during the second development due to the force received from the electric field.

■ Detected by the charged image sensor 9a by the ion recording head 20, and the signal processing circuit 9b
The ion recording head 20 that receives the signal of the red image area determined by charges the red image area and its vicinity (
(See Figure 4(e)). At this time, the ion recording head 20
The head bias was -1500 (V), the surface potential of the black part was -100 (V), the surface potential of the white part was -50 (V), and the potential of the charged part was -800 (V).

■With the second exposure optical filter 8 switched, the reflected light from the original 1 is irradiated, and a second positive latent image is formed (see Fig. 4).
f)). At this time, the surface potential of the red image area is -800
(v), the surface potential of the black image area was -100 (V), and the surface potential of the white area was -50 (V).

■ Red toner is attached to the second positive latent image formed on the second red developing photoreceptor IO by the second developing device 14, and a second developed image is formed (see FIG. 4(g)). ). At this time, 2 of 10 charges
component-based red toner is used, and the developing bias VB
2 was -250 (■).

(2) Transfer The first and second toner images formed on the photoreceptor 10 are collectively transferred onto the recording sheet 30 by the transfer corotron 16a. At this time, since there is a difference in potential level between the black image part and the red image part, the potentials are equalized by the pre-transfer corotron 15 and then transferred.

In the first and second development, the developing unit 13 that does not perform one development. 14 must be retracted to a position away from the photoreceptor 10, or the ears must be removed from the sleeve of the developing roll 34. Further, during the first rotation of the photoreceptor 10, the pre-transfer corotron 15 and the transfer corotron 16
a1 peeling corotron 16b and static elimination lamp 19 are OFF
Therefore, the cleaning device I8 is in a state separated from the photoreceptor surface. Further, during the second rotation of the photoreceptor IO, the charger l1 is turned off.

◎Second Embodiment FIGS. 5(a) to 5(h) are explanatory diagrams showing a case where a part of a black image area is converted to red.

Conversion of a part of the black image area to red can be performed by the steps shown below.

(2) Charging The surface of the photoreceptor 10 is uniformly charged to -800 (V) by the charger 11 (see FIG. 5(a)).

(1) First Exposure The reflected light image from the original 1 is exposed onto the photoreceptor 10 to form a first positive latent image (see FIG. 5(b)).

At this time, the surface potential of the black part was -800 (V), and the surface potential of the white part was -100 (V).

■Color conversion unit Charging The area to be color converted after the first exposure is set to white area level -100 (V
) (see Figure 5(C)). Note that the color conversion area can be specified using a digitizer or the like.

■The first positive latent image formed on the first black developing photoreceptor 10 is coated with black toner by the first developing device 13 to form a first developed image (see FIG. 5(d)). ). At this time, 2 of 10 charges
A component-based black toner is used, and the development bias is -
It was 250 (V).

(2) Static Elimination Static electricity is removed from the surface of the photoreceptor by the AC voltage applied to the corotron 17 (see FIG. 5(e)).

At this time, the surface potential of the black part was -100 (V), and the surface potential of the white part was -50 (V).

(2) Charging by the ion recording head 20 The color conversion section and its vicinity are charged by the ion recording head 2θ (see FIG. 5(f)). At this time, the head bias of the ion recording head 20 is -1500 (V), the surface potential of the black part is -100 (V), and the surface potential of the white part is -50 (V).
V), and the potential of the charging part was -800 (V).

■With the second exposure optical filter 8 switched, the reflected light from the original 1 is irradiated, and a second positive latent image is formed (see Fig. 5).
g)). At this time, the surface potential of the color conversion area is -80
0 (V), the surface potential of the black image area was -100 (V), and the surface potential of the white area was -50 (V).

■ Red toner is attached to the second positive latent image formed on the second red developing photoreceptor 10 by the second developing device 14, and a second developed image is formed (see FIG. 5(h)). ). At this time, 2 of 10 charges
component-based red toner is used, and the developing bias VB
2 was -250 (V).

(2) Transfer The first and second toner images formed on the photoreceptor 10 are collectively transferred onto the recording sheet 3o by the transfer corotron 161. At this time, since there is a difference in potential level between the black image part and the red image part, the potentials are equalized by the pre-transfer corotron 15 before being transferred.

This color conversion can be performed simultaneously with the two-color copying of the first embodiment.

◎Third Embodiment FIGS. 6(a) to 6(f) are explanatory diagrams in the case of adding a red image to a black monochrome copy.

Addition of a red image to a black monochrome copy can be performed by the steps shown below.

(2) Charging The surface of the photoreceptor 10 is uniformly charged to -800 (V) by the charger 1l (see FIG. 6(a)).

(2) Exposure The light image reflected from the original 1 is exposed onto the photoreceptor 10 with the red area removed by the optical filter 8 to form a first positive latent image (FIG. 6(b)) reference).

At this time, the surface potential of the black part was 800 (V), and the surface potential of the red and white parts was -100 (V).

(2) Development Black toner is attached to the first positive latent image formed on the photoreceptor 10 by the first developing device 13 to form a first developed image (see FIG. 6(c)). At this time, 2 of 10 charges
component-based black toner is used, and the developing bias VB
I was -250 (V).

(2) Static Elimination Static Elimination Static electricity is removed from the surface of the photoreceptor by the AC voltage applied to the corotron 17 (see FIG. 6(d)).

At this time, the surface potential of the black part was -100 (V), and the surface potential of the white part was -50 (V).

■After the writing charge is removed by the ion recording head 20, a positive latent image for additional recording is formed by the ion recording head 20 (
(See Figure 6(e)). In this case, the additional information can be selected or input using additional information selection means, input means, etc. (not shown).

■ Red toner is attached to the write-once positive latent image formed on the second red developing photoreceptor 10 by the second developing device 14, and a second developed image is formed (see FIG. 6(f)). . At this time, 2 of 10 charges
component-based red toner is used, and the developing bias VB
2 was -250 (V).

(2) Transfer The first and second toner images formed on the photoreceptor 10 are collectively transferred onto the recording sheet 30 by the transfer corotron 16a. At this time, since there is a difference in potential level between the black image part and the red image part, the potentials are equalized by the pre-transfer corotron 15 before being transferred.

Note that the color addition described above can be performed simultaneously with the color copying and color conversion of the first and second embodiments.

Furthermore, additional color writing can also be performed in monochrome copying using black or red in the same color. In this case, after copying is performed in the first cycle of the photoreceptor 10, a positive latent image for additional writing may be formed using the ion recording head 20, and development may be performed with toner of the same color as in the 2nd cycle.

In the above embodiment, the case of copying black and red has been described, but of course, two-color copying, color conversion, and color addition can be similarly performed with other colors.

[Effects of the Invention] As explained above, since the color recording method and apparatus of the present invention are configured as described above, the following effects can be obtained.

I) Since the ion recording head is used, it becomes possible to perform two-color copying by two-color overlapping development using a positive latent image using an analog optical system, which was previously impossible, and prevents the occurrence of color mixture in the image. I can do it.

2) Since the ion recording head can be used as a local charger, high resolution is not required, and it can be used at about 100 pixels/inch. It is also used for forming latent images in the additional writing section.
About pixels/inch is sufficient. Furthermore, high resolution is not required for the image sensor as well, and 200 pixels/
Since components with a low resolution such as an inch size are sufficient, costs can be reduced.

3) Since a two-color image is formed by two rotations of the photoreceptor, it is possible to copy at a higher speed than with a two-transfer method, and to achieve highly accurate registration.

4) Since an electrostatic latent image is formed using a two-color analog optical system, high image quality equivalent to that of conventional copying devices can be guaranteed.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a color recording device according to the present invention;
FIG. 2 is a perspective view of the ion recording head in this invention;
Figure 3 is a sectional view taken along line mm in Figure 2, and Figures 4 (a) to (g).
is an explanatory diagram showing the two-color copying process in the first embodiment of this invention, FIGS. 5(a) to (h) are explanatory diagrams showing the color conversion process in the second embodiment of this invention, and FIG. (a) to (f) are explanatory diagrams showing the color conversion process of a third embodiment of the present invention. Code explanation (5)...Half mirror (optical path splitting means) (7)...
・Analog optical system (8)...Optical filter (color separation means) (9!)...
・Image sensor (image reading means) (9b)...Signal processing circuit (color discrimination means) (10)...Photoconductor (electrostatic latent image carrier) (11)...Charger (13)・...First developing device (first developing means) (14
)...Second developing device (second developing means) (20)...Ion recording head patent applicant Fuji Xerox Co., Ltd. Agent

Claims (2)

[Claims] (1) After the electrostatic latent image carrier is uniformly charged, a first positive latent image is formed by exposing reflected light from the document with a specific color separated by a color separating means, and the first positive latent image is A first step of developing the latent image with a first toner, and after rotating the electrostatic latent image carrier once, only the area of the electrostatic latent image carrier corresponding to the separated specific color area of the document is developed. is selectively charged, and the electrostatic latent image carrier is exposed to light reflected from the document that does not pass through the color separation means to form a second positive latent image; 2. A color recording method comprising: a second step of developing with a second toner. (2) an electrostatic latent image carrier, a uniform charging means, an ion recording head, an optical means including a color separation means for guiding reflected light from a document onto the electrostatic latent image carrier, and the optical means; an optical path dividing means provided in the optical path; an image reading means provided in the divided optical path; and a color determining means for determining a specific color area in the document based on the output of the image reading means; A color recording apparatus comprising a plurality of developing means for regularly developing a positive latent image formed on the electrostatic latent image carrier.